The skin is said to be “a mirror reflecting who you are inside”. Indeed, beauty is not simply one’s external appearance, but it also comes from within; beauty also comes from paying attention to both physical and mental health. Attention to have attractive skin has been on the rise in many age groups over the last decade; even women in their 20’s often expresses the desire to look younger and fresher. Products containing collagen peptides drive the growth of the health and beauty and food and beverage industry. These products moisturize the skin, leading to their widespread popularity. Oral intake of collagen peptides has been found to increase the moisture content of the stratum corneum, thereby increasing the moisturizing capacity of the skin. Hydroxyproline (Hyp), produced as a result of digesting collagen peptides, increases the expression of serine palmitoyltransferase-2 and β-glucocerebrosidase, enzymes involved in ceramide synthesis in the stratum corneum. When taken orally, collagen peptides are absorbed by the body as Hyp or dipeptide, and this is believed to improve the moisturizing capacity of the skin by increasing the amount of ceramides in the stratum corneum. Consuming foods that beautify the skin is essential to maintain beautiful and healthy skin. Ingredients with skin-enhancing effects are absorbed by the body when ingested as food, and then distributed throughout the skin. This provides effective skin clarifying and anti-aging benefits. Substances that offer these actions are attracting the attention of not only consumers but also researchers interested in the science of beauty.